In the title compound, C16H22N3OP·H2O, the P atom adopts a distorted tetrahedral environment with the bond angles around the P atom in the range 99.98 (7)-116.20 (7)°. The P-N bond length in the [(CH3)2N]P(O) fragment [1.6392 (14) Å] is slightly shorter than two other P-N bonds [1.6439 (15) and 1.6530 (14) Å]. In the (CH3)2NP(O) fragment, one of the methyl groups is syn to the P=O bond, whereas the other one is anti to the P=O bond [C-N-P=O torsion angles = 4.80 (17) and -174.57 (15)°]. In the crystal, the water molecules form hydrogen bonds to the O atoms of the P=O bond of two different molecules and act as acceptors for the two amino H atoms of the same molecule. As a result, chains parallel to [010] are formed.

The crystal structure determination of the title hydrate phosphoric triamide
(Fig. 1) was performed as a part of work on synthesis and X-ray
crystallography of compounds with a [(CH3)2N]P(O) fragment (Pourayoubi,
Tarahhomi et al., 2012; Pourayoubi et al., 2011).

In the phosphoric triamide molecule, the P atom adopts a distorted
(N)P(O)(N)2 tetrahedral environment. The P═O and P—N bond lengths are
within the expected values (Pourayoubi, Tarahhomi et al., 2012;
Pourayoubi et al., 2011).
The sum of three bond angles at the nitrogen
atom of the
dimethylamido fragment, C11—N3—C10 + C11—N3—P1 +
C10—N3—P1, of 360° suggests sp2 hybridization for this N atom.
Moreover, the C6—N1—P1 and C4—N2—P1 bond angles
are 125.07 (12)° and 125.66
(12)°, respectively. The P—N bond length of the [(CH3)2N]P(O) fragment
is shorter than two other P—N bonds.

In the crystal, the oxygen atoms of phosphoryl group and water molecule act as
double-hydrogen bond acceptors (for a definition of double-hydrogen bond
acceptor, see: Pourayoubi, Nečas & Negari, 2012) to form
O—H···O···H—O
and N—H···O···H—N groups. The phosphoric triamide and water molecules are
aggregated through these hydrogen bonds in a linear arrangement parallel to
the b axis, Fig. 2.

Synthesis of ((CH3)2N)P(O)Cl2: [(CH3)2NH2]Cl (0.184 mol) and
P(O)Cl3 (0.552 mol) were refluxed for 8 h and afterwards the excess of
P(O)Cl3 was removed in vacuo.

Synthesis of title compound: To a solution of ((CH3)2N)P(O)Cl2 (3.7 mmol)
in CHCl3 (15 ml), a solution of ortho-toluidine (14.8 mmol) in the
same solvent (25 ml) was added at 273 K. After 4 h stirring, the solvent was
removed and product was washed with deionized water and recrystallized from
chloroform/n-hexene at room temperature to yield colourless crystals.

The H1N, H2N, H1W and H2W atoms were found from a Fourier difference map and
their coordinates were refined with the following restraints:
N—H = 0.87 (2) Å, O—H = 0.85 (2) Å and H1W···H2W = 1.33 (2) Å.
Their displacement parameters were set to
1.2 Ueq of the parent atom. All other
hydrogen atoms were placed in calculated positions and allowed to ride on
their parent C atoms; C—H distances (CH3) 0.98 Å, (CH) 0.95 Å with
Ueq of 1.5 and 1.2, respectively.

Fig. 1. An ORTEP-style plot and atom labeling scheme for the title
hydrate compound. Displacement ellipsoids are given at 50% probability level
and H atoms are drawn as small spheres of arbitrary radii.

Fig. 2. Packing in the title compound with hydrogen bonds shown as dotted
lines. Only H atoms involved in hydrogen bonds are shown.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor
wR and goodness of fit S are based on F2, conventional
R-factors R are based on F, with F set to zero for
negative F2. The threshold expression of F2 >
σ(F2) is used only for calculating R-factors(gt) etc.
and is not relevant to the choice of reflections for refinement.
R-factors based on F2 are statistically about twice as large
as those based on F, and R- factors based on ALL data will be
even larger.